Carburetor for internal-combustion engines



C. BROWN.

CARBURETOR FOR INTERNAL COMBUSTION ENGINES.

APEHCATION FILED OCT-15,19IB.

Patented July 11, 1922.

EET 1- 2 SHEETSSH 0. BROWN. CARBURETOR FOR'INTERNAL COMBUSTION ENGINES.

APPLICATION FILED OCI- I5, I9I8.

Patented J ul 3' 11, 1922.

2 SHEETS SHEET 2.

CLEMENT BROWN, OF IBIRCHFIELID, BIRMINGHAM, ENGLAND.

CARBURETOR FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented July 111, 11922..

Application filed October 15,1918. Serial No. 258,227.

To all whom it may concern Be it known that I, CLEMENT BROWN, 8 subject of the'Kingdom of Great Britain, residing at 19 Trinity Road, Birchfield, Birmingham, in the county ofiVVarwick, England, engineer, have invented certain new and useful Improvements in or Relating to Carburetors for Internal -Combustion Engines, of which the following is a specification.

a This invention comprises certain improvements in or relating to carburetors for internal-combustion engines, and it relates to the type of carburetor in which the fuel supply orifice is regulated or adjusted by a member, the cross-sectional area of which varies longitudinally of said member. such a member having before been operated by or in accordance with the movements of the throttle valve.-

By the present inventlon, a member, the CIOSS*S8Ci3lOIl of which varles uniformly, may

be adapted to regulate the orifice by a move-- ment which is not in proportion to the movement of the throttle valve, as for instance by a process which accurately regulates the orifice in accordance with any position which the throttle valve may assume. I carry out the present invention by displacing the fuel regulating member by a cam operated by or in accordance with the throttle valve, and which cam may be of any shape desired to appropriately displace the fuel regulating member.

The posltion of this cam may be adjustable, and the provision for this adjustment may be such that adjustment may be effected from a distance'while the engine is working.

In order that this-invention may be clearly understood and readily carried into practice, reference may be had to the appended'explanatory drawings, in which Fig. 1 illustrates in elevation a carburetor according to the present invention.

Fig. 2 is a section transversely of the main air passage, the section being taken on line 2-2 of Fig. 3, and

Fig. 3 is a section on line Fi .2.

n a convenient embodiment of the pres ent invention, the carburetor comprises a tubulus a of length which is short in relation to the diameter. The internal surface of this tubulus converges towards the centre from both extremities. At a point slightly to the mixture outlet side of the point of maximum convergence of this tubulus which constitutes the main air conduit, a plate 6 is incorporated adapted to slide transversely across the conduit. This plate is adapted to function as the throttle valve and it has a circular opening 0 adapted to register with the conduit. This plate may be displaced transversely of the conduit to more or less closethe latter. The arrangement is such that-when the throttle valve is in the full open position the stream line or other internal form of the'main air passage is unbroken or substantially unbroken.

At a position adjacent to, and on the air inlet side of, the plate, and slightly to the mixture outlet side of the point of maximum constriction of the air conduit, openings 0 are incorporated. These openings communicate with a tubular space 9 which is provided tangentially within the wall of the air conduit. A liquid fuel jet r is incorporated within the one extremity of this tubular space q; this liquid fuel orifice receives liquid fuel direct from-the main source of supply, a float chamber or the equivalent being unnecessary. The delivery of liquid fuel from this orifice is controlled by a taper needle 8, the taper of which is uniform, that is to say, strictly conical. With the tubular space at a position in the vicinity of the orifice, an air conduit t may communicate. The liquid fuel may or may not be supplied under pressure. When the throttle is closed, the taper needle is adapted to effectively close the orifice and prevent leakage of fuel. In the embodiment shown in the drawing, the tubular space 9 is located vertically to the right of the main air passage. Within the wall of this main air passage on the air inlet side of the throttle valve 6, a concentric channel or conduit 37 is provided. With this annular conduit the tubular space containing the orifice is in communication and the openings 0 extend radially from the said annular conduit intothe main air passage of the carburetor, these radial fuel delivery orifices being located at intervals around the circumference delivery orifices in the lower part of the main air conduit. The plunger (1 projects out of the tubular housing and is furnished wvith a head or enlargement by virtue of which it is adapted to be operated by a cam e. Said cam may be carried by a bar 7 adapted to slide in the plane of, and in the path which is parallel with that of, the throttle valve bf The throttle valve and cam bar are adapted to be collectively operated by a link g. This link is at its one extremity pivoted to a bell crank lever 72. which is in turn pivoted to a suitable part of the carburetor. body. The link is at approximately the middle of its length connected by a member 2' to the throttle valve, and at its extremity remote from the end at which it is pivotally connected to the carburetor body, said link is appropriately pivotally coupled to the cam 6. By virtue of this construction the cam bar has a movement considerably greater than that of the throttle valve. The cam is furnished with an inclined surface which so cooperates with the plungerd by which the taper needle is carried that longitudinal movement of the cam efi ects the dearm I: of the lever is coupled by a control ro Z to any appropriate control provision;

The position of the bell crank lever, and

thus the pivot of the operating link 9 which is coupledto the throttle and cam, may be i .to secure by Letters Patent is at any suitable position,.

varied. According to the position of this link the angular position of the cam e in relation to the slide f is varied. The operated extremity of the cam which may be pivotally coupled to an operating rod m at the connection with the operating link '9, thus moves through an arc, the radius of which corresponds with the length of the operating link 9 which is coupled to the throttle valve, and the position of which depends upon the position of the pivot of said operating link,

A spring controlled pivoted arm or lever n is adapted to co-operate with the head of the plunger (Z in order to retain the latter in appropriate co-operation with the cam surface.

The cam surface may be mathematically designed to so operate the taper needle that the correct quantity of liquid fuel is delivered to admix with the quantity of air-admitted at every position of the throttle.

What I claim as my invention and desir In a carburetor, a main air passage, a throttle valve controlling said passage, a fuel orifice, a cam moving parallel to said throttle valve, a guide to which said cam is pivoted, a member actuated by said cam for controlling said orifice, means for simultaneously moving said cam and said throttle valve, and means acting on said first named means for moving said cam on its pivot independently of said throttle valve.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

CLEMENT BROWN.

Witnesses:

EDGAR N. WHEELER, KATHLEEN M. THOMPSON. 

